US3115999A

US3115999A - Apparatus for intermittent web feeding

Info

Publication number: US3115999A
Authority: US
Inventors: Frederick J Wythe
Original assignee: Emhart Manufacturing Co
Current assignee: Emhart Manufacturing Co
Priority date: 1961-07-25
Filing date: 1961-07-25
Publication date: 1963-12-31
Anticipated expiration: 1980-12-31
Also published as: GB1018062A; CH414296A; BE620662A

Description

Dec. 31, 1963 F. J. WYTHE 3,115,999

v APPARATUS FOR INTERMITTENT WEB FEEDING Filed July 25, 1961 5 Sheets-Sheet l FIGII INVENTOR. 3 FREDERICK J. WYTHE m N 20 ATTORNEYS cu cu N Dec.- 31, 1963 'F. J. WYTHE APPARATUS FOR INTERMITTENT WEB FEEDING 3 Sheets-Sheet 2 Filed- July 25. 1961 INVENTOR.

FREDERICK J. WYTHE A TTORNE Y5 BY .QM'L, M Maw- Dec. 31, 1963 F. J. WYTHE 3, 9

. APPARATUS FOR INTERMITTENT WEB FEEDING Filed July 25. 1961 A 3 Sheets-Sheet s INVENTOR.

FREDERICK J. WYTHE BY M, g WM/M A TTORNE YS United States Patent M 3,115,999 APPARATUS FOR INTERMITTENT WEB FEEDING Frederick J. Wythe, Hebron, Conn, assignor to Emhart Manufacturing Company, Hartford, Conn, a corporation of Delaware Filed July 25, 1951, Ser. No. 126,606 9 Claims. (Cl. 226-33) This invention relates to an apparatus for effecting controlled intermittent feeding of a web having spaced registration indicia.

In the molding, cutting, packaging, printing and other arts, where material on which Work is to be performed is supplied from a web, it is conventional to intermittently feed the web to a work station such that a particular work operation may be performed upon a predetermined Web increment. During such operations, it is imperative that the web increment positioned at the work station be in precise registration with the work performing apparatus.

To secure proper registration of web portions, it has been the usual practice to imprint or otherwise form longitudinally spaced registration indicia on Webs, which indicia, at times, have constituted a portion of a printed de sign. By then using devices such as photocell units to scan the webs, it has been possible to achieve some degree of registration correction by correlating the feed with the location of indicia by the scanning unit.

Registration techniques previously employed have been characterized by several operational defects. For example, many registration arrangements, while detecting registration errors during feed strokes, have not acted to correct these errors until succeeding strokes. In addition, such arrangements, rather than applying a complete feed correction, frequently have introduced minute incremental corrections of predetermined extent over a period of several feed strokes until the overall error was remedied.

Some attempts have been made at effecting feed corrections during abnormal feed strokes. In this corrective technique, however, it has been the practice to reposition the web before each feed stroke to insure the proper feed. Where a web has been enmeshed with feed rolls or other gripping components of a work performing apparatus, this form of registration correction has required complex web releasing arrangements and introduced a serious likelihood of web tearing occurring during the corrective web movement.

Conventionally, the scanning of webs to ascertain the degree of web registration has been performed during high speed feed strokes. Because of the relative high speed movement of webs past scanning units, frequent errors have been introduced in the feed corrections themselves.

Because of mechanical linkages generally employed between scanning units and feed correction mechanisms, it has proven to be diflicult to accommodate registration controlled feed apparatus to variations in web dimensions and positioning of registration indicia.

Recognizing the need for an improved technique of controlled registration feeding of a web, it is an object of this invention to provide an apparatus for eifecting consistently accurate intermittent web feeding.

It is a further object of this invention to provide such an apparatus in which each feed stroke is regulated to insure the precise registration of the web increment upon which work is to be performed.

It is an additional object of the invention to provide such an apparatus in which high speed intermittent feed strokes are imparted to a web subsequent to determinations of proper feed stroke increments, which determina 3,ll5,99 Patented Dec. 31, 1963 tions result from the scanning of the web at relatively low speed while the web is at rest.

It is a final object of the invention to provide an apparatus including hydraulic and electronic control means to facilitate the positioning of the scanning unit in relation to varied positions of web carried registration indicia.

The apparatus envisioned for performing this invention includes cyclic feed means for imparting intermittent feed strokes to a web and feed stroke resetting means for restoring the feeding means to a feed stroke initiating position at the end of each feed stroke while the web is at rest. Feed stroke adjusting means are provided for determining the initiating position of each feed stroke during the restoring of the feeding means. The adjusting means includes scanning means for translating longitudinally along the web in a direction opposite to the feed direction to locate a registration indicia. Also included in the adjusting means are control means responsive to the location of the indicia by the scanning means for terminating the restoring of the feed means to thus determine the feed initiating position.

In describing the invention, reference will be made to a preferred embodiment of the apparatus which is schematically represented in the accompanying drawings in which:

FIGURE 1 is a schematic representation of the feed apparatus as employed in combination with a plastic molding machine;

FIGURE 2 is a partially sectionalized schematic representation of the preferred hydraulic circuit employed for actuating the Web feeding and web scanning portions of the apparatus; and

FIGURE 3 is a schematic representation of a control system employed to correlate the feeding and registration correction of the web with the plastic molding operation.

A molding Work station 1 is illustrated in FIGURE 1 as including a stationary platen 2 supported by frame member 3. A reciprocable mold 4 having a mold cavity 5 is positioned in facing relationship with the platen and provided with elevating means such as a piston rod extending from hydraulic cylinder 6. A web 7 of plastic material is supplied from a roll 3 and conveyed by means of feed means 9 to the molding station. Web 7 passes through the station between reciprocable mold 4 and stationary platen 2. In leaving the station, web 7 is engaged by outfeed means 10 which draws the molded portion of the web away from the molding station.

Feed means '9 includes an idler roll 11 positioned below web 7. Idler roll 11 is supported at one end of a pivoted link 12 and connected by a link 13 to one end of a crank 14 pivotally' supported at a pivot point 15. The other end of crank 14 is engaged by a piston operated rod 16 extending from a cylinder 17. By extending rod 16, crank 14 will be pivoted so as to draw link 13 down- Wardly and thus disengage the idler roil 11 from web 7. It is to be appreciated, of course, that the linkage and crank assembly will be duplicated at both ends of the idler roll to insure uniform roll movement transverse to web 7.

A feed roll 18, mounted above web 7, is parallel to idler roll :11. Feed roll 18 is journaled at opposite ends in a frame, a portion of 'which is shown schematically as plate 19.

A cyclic motor 20 is employed to impart cyclic rotary motion to feed roll 18 through a connecting drive chain including drive gears 21 and 22. Cyclic motor 20 is a rotary piston motor, one commercial form of which is known as a Rotac Actuator.

Outfeed means 10 essentially correspond to the struc ture of drive means 9. The outfeed assembly includes an idler roll 23 mounted at one end of a pivoted link-'24. A link 25 extending downwardly from roll 23 is engaged by one end of a crank 26 which is pivotally mounted at a pivot point 27. The other end of crank 26 is pivotally attached to a piston operated rod 23 extending from a cylinder 29. As with the arrangement for supporting the idler roll in the feed means, the outfeed idler roll supporting mechanism is duplicated at each end of roll 23.

An outfeed roll 36* positioned above web 7 is driven by a cyclic hydraulic motor 31 through a gear chain including gears 32 and 33. Motor 31 is also a rotary piston motor and is of the same size as motor 28 employed in feed means 9.

For longitudinally scanning .web 7, scanning means carried on a longitudinally movable rod 34 are employed. The scanning means include a light source 35 which directs a beam of light against web 7 and a photocell sensing unit 36 adapted to receive light reflected from web 7 by registration indicia 37 which are longitudinally spaced along the web.

To correlate the operation of the molding unit, the web feeding mechanism, and the scanning means, cam control means are employed which are driven by cyclic feed motor Included in this cam means are separate

rotary cams

38, 39, and 40, the individual functions of which will hereafter be delineated.

With the apparatus in operation, cyclic motors and 31 will concurrently drivingly engage web 7 to effect intermittent feed and outfeed strokes so as to bring succeeding portions of the web into registered alignment with mold 4 and transport molded web portions away from the mold. After a web increment has been properly registered, the mold will engage the web 7 to press it against the paten 2 and effect a molding operation. During this operation, idler rolls 11 and 23 will move away from web 7 such that driving rolls 18 and 30 are disengaged from driving engagement with web 7. While the web is at rest and after thisdisengagement, the cyclic

rotary piston motors

20 and 31 will be reset to a feed initiating position.

The resetting of the cyclic motor 20 is governed by the scanning unit. During the resetting of the motors, and with the web at rest, the photocell mounting and actuating rod34 is moved longitudinally of the web and opposite to the feed direction until a registration indicia 37 is located. Through a suitable control circuit, a signal is generatedby the scanning unit in response to the location of the indicia, which signal terminates the resetting of motor 20'. By positioning the scanning unit such that the distance of the sensing point, i.e. photocell 36, from the desired registration point in the mold corresponds at any particular time to the feed stroke which would be imparted by rotary motor 20, precise registration during each feed stroke is positively insured.

The hydraulic circuit employed in the feed and registration mechanism is schematically illustrated in FIGURE 2. The pressurized fluid. supply portion of the system includes a liquid source 41, a pump 42, and an accumulator 43, all conventionally arranged in series fluid connection to supply pressurized fluid to input conduit means A. To prevent back flow through the supply portion of the system, a check valve 44 is provided, while a pressure relief valve 45 is included to vent the system in the event of the existence of excessive system pressures.

Feed motor 20* includes cylindrical casing 2th: and rotary piston 26b pivotally mounted on axle 200. A separating partition, or stop 20d is positioned between casing openings 20s and 20 Outfeed motor '31, dimensioned identically to feed motor 20, includes cylindricalcasing 31a, rotary piston 31b pivotally mounted on axle 31c, and partition 31d between openings 31a and 31 A solenoid actuated spool valve 46 determines the direction of fluid flow through feed motors 2.0 and 31 so as to govern their direction of rotation. A solenoid actuated spool valve 47 determines whether motors 20* and 31 are arranged in series or parallel fluid connection. With their respective solenoids deenergized, the spools of

valves

46 and 47 are centered in the illustrated positions by conventional return springs. 7

Both spool valve dd and spool valve 47 are of the tfour-way type, each including four openings disposed as a pair a and b on one side and a pair 0 and d on the opposite side. Valve 46 includes a solenoid 48 on its right end which, when actuated, moves the valve spool to the left so as to place openings a and c in fluid communication and openings b and d in fluid communication. A solenoid 49- on the left end of the valve 46, when actuated, moves the valve spool to the right so as to place openings a and d in fluid communication andopenings b and c in fluid communication. In the illustrated rest position, openings a and c are in fluid communication while openings b and d are mutually sealed from each other.

A single solenoid 50 in valve unit 47, when actuated, urges the spool in this valve to the left so as to place openings a and d in communication and openings b and c in communication. In the normal rest position illustrated, openings b and d are in communication while openings a and c are sealed from each other.

To interconnect the flow controlling solenoids and the rotary motors, a series of conduits are employed. Conduit means B extends from opening a in valve 46 to opening 31 in outfeed motor 31. Conduit means C extends from opening 31a in this motor to opening b in solenoid 47. Conduit means D extends between opening a in valve 47 to opening 26 in feed motor 20. From opening Zlle in feed motor 20, conduit means E extends to opening b in valve 46. From opening d in valve 46, conduit means F extends to a composite drain network discharging into a liquid sump, which is illustrated as source 41. A branch conduit means G extends from conduit means B to opening a in valve 47. From opening 0 in valve unit 47, conduit means H extends to conduit means F for discharge to sump 41.

For flow rate control purposes, a series of flow restricting or speed control units are incorporated in the circuit. In conduit means B, a flow restricting valve 51 is placed in series connection. Valve 51 includes a check valve 51a permitting flow from opening a of valve unit 46 and an adjustable annular orifice 51b for restricting flow toward this opening. A piston accumulator 52 is also placed in series fluid connection with conduit means B but arranged in parallel fluid connection with flow restricting valve 51. Accumulator 52 includes freely slidable, rod carrying piston 52a and threadably adjustable stop 52b for determining the innermost terminal position of piston 52a.

A flow restricting valve 53 is placed in series connection in conduit means E between opening Ztie of motor 20 and opening b of spool valve unit 46. Valve 53 includes check valve 53a to permit flow from opening b of valve 46 and an adjustable annular orifice 53b for restricting flow to this opening.

In conduit means H, a flow restricting valve 54 is pro vided. Valve 54- includes an adjustable annular orifice 54a for restricting flow through this conduit means.

With the apparatus arranged as illustrated, i.e. with

solenoids

48, 49, and 5t) deenergized, there will be no flow through the system due to the non-interconnected character of openings b and d of spool valve unit '46 and openings a and c of spool valve unit 47. However, as fluid communication will exist across piston 52a of accumulator 52 through means of valve 51, and because of the'difference in area on opposite sides of this piston, the piston will extend to the right owing to the greater fluid pressure being exerted on its head end.

Clockwise feed and outfeed rotation respectively of

rotary pistons

20b and 31b is effected by actuating solenoid 49. Such actuation moves the spoolof valve 46 to the right so as to place conduit means A and E in fluid communication. Pressurized fluid thus flows from conduit means A through conduit means E to opening 20c of feed motor 20. The clockwise movement of rotary piston 20b displaces fluid through opening 201 into conduit means D. This fluid flows through spool valve 47 through its interconnected openings d and b into conduit means C and into opening 31e of rotary motor 31. The clockwise movement of rotary piston 31d, as effected by the fluid entering opening 31e, displaces fluid through opening 31f into conduit means B. In flowing through conduit means B, because of the restriction in valve 51, the fluid will initially tend to flow into accumulator 52 so as to move the piston 52a to the left until it engages the adjustable stop 52b. Fluid displaced by the head end of piston 52a will flow through conduit means B and through interconnected openings a and d of spool unit 46 into conduit means F from which it discharges into sump 41.

The freely slidable character of piston 52a allows the accumulation of flow within accumulator 52 at a relatively rapid rate. When the piston movement is interrupted by stop 52b, however, flow is then forced to pass through annular orifice 51b of valve 51. The restricted character of this orifice, of course, substantially reduces the rate of fluid flow through conduit means B. By dimensioning the fluid accumulation cavity in fluid accumulator 52 so as to be of less volume than the fluid displaced from motor 31, the clockwise motion of rotary piston 31b will be slowed at an intermediate point in its rotary travel.

As heretofore demonstrated, the energization of solenoid 49 causes fluid to flow to series connected

fluid motors

20 and 31 to effect clockwise movement of the motor pistons and thus impart concurrent feed and outfeed strokes to web 7. Where resetting of the motors is to be accomplished at the end of feed strokes,

solenoids

48 and 50 are energized to place

motors

20 and 31 in parallel fluid connection and to eifect counterclockwise rotation of

rotary pistons

20b and 31b.

By energizing solenoid 48, the spool of valve 46 is moved to the left so as to place conduit means A in communication with conduit means B and conduit means E in fluid communication with conduit means F. The energization of solenoid 50 moves the spool of valve 47 to the left so as to place conduit means G and D in fluid communication and conduit means C and H in fluid communication.

With both

solenoids

48 and 50 energized, fluid will flow from supply source 41 through conduit means A and into conduit means B. Because of the branched connection of conduit means G with conduit means B, fluid flow through conduit means B will divide at the junction of conduit means B and G to flow in parallel to

fluid motors

20 and 31. The portion of flow continuing through conduit means B to opening 31 in motor 31 effects counterclockwise rotation of rotary piston 31b. Fluid displaced by this movement of piston 31b flows from opening 31e into conduit means C and through connected openings and b of spool valve unit 47 into conduit means H. Flow through conduit means H discharges into conduit means F and subsequently flows to sump 41. The portion of the divided flow entering conduit means G flows through connected openings a and d of spool valve unit 47 into conduit means D. The flow in conduit means D enters opening in feed motor 20 to drive rotary piston 20b counterclockwise. Fluid displaced by the counterclockwise movement of piston 20b leaves opening 20a to enter conduit means E. Flow through conduit means E passes through the fluid interconnected openings b and d in spool valve unit 46 to enter discharge conduit means F for flow to sump 41.

Adjustable valve units 53 and 54 regulate and control the rate of counterclockwise piston movement. Valve 53 restricts discharge flow from feed motor 20 while valve 54 restricts discharge flow from outfeed motor 31.

For the purpose of translating the scanning unit longitudinally of web 7, driving means are provided which are actuated by a rotary cam 38 driven by feed motor 20'. As illustrated, rotary cam 38 includes a partially circular portion and an elongate camming portion. A cam follower engaging the periphery of the cam will remain stationary while in engagement with the circular portion and will be actuated only when the cam is rotated sufficiently to bring it into contact with the elongate cam portion.

The driving means for the scanning unit which is operated by the motor driven cam 38 includes a first, piston type, hydraulic motor 55, a second, piston, type, hydraulic motor 56, and a spool valve 57.

The first hydraulic motor 55 includes a piston 55a from which a piston rod 55b extends to terminate in a cam follower 55c engaging the periphery of cam 38. The second hydraulic motor 56 includes a piston 56a from which rod 34 extends to support the photocell scanning unit.

Spool valve 57, being of the four-way type, includes a pair Olf openings a and b on one side of the valve body and openings c and d on the other side. A solenoid 58 is provided for moving the spool of the Valve to effect various communication arrangements between the valve openings. As illustrated, with solenoid 58 deenergized, opening a is in fluid communication with openings b and d. When solenoid 58 is energized to translate the spool to the left, openings b and c are placed in fluid communication while openings a. and d are sea-led from each other.

To supply fluid to hydraulic motors 55 and '56, branch conduit means I are provided which extend from supply conduit means A to opening a in spool valve 57. Conduit means I extends from opening b of this valve to the head end of the cylinder of hydraulic motor 56. Conduit means K extends from opening d of valve unit 57 and branches to communicate with the head end of the cylinder of hydraulic motor 55 and the rod end of the cylinder of hydraulic motor 56. Conduit means L extends from opening 0 of valve unit 57 to communicate with the network discharging into sump 41.

With solenoid 58 deenergized, pressurized fluid supplied through conduit means I enters opening a of valve unit 57 to pass through conduit means I to the head end of piston 56a and through conduit means K to the rod end of piston 56a and the head end of piston 55a. Pressurized fluid acting on the head end of piston 55a will urge the piston to the left to bring carn follower 550 into engagement with cam 38. To facilitate this 'leftward movement, the rod end of piston 55a may be vented to the atmosphere or a partial vacuum condition may be created in this portion of the cylinder. In any event, even absent the venting or vacuum conditions, the hydraulic force imposed on the head end of the piston will be suflicient to move the piston to the left, even against the resistive force of compressed air which might be in the rod end of the cylinder. Through conduit means I and K, fluid will act on opposite sides of piston 56a of the second hydraulic motor 56. Because of the larger exposed area on the head end of this piston, and the common source of fluid pressure, the piston will translate to the left.

When during the operation of the apparatus, translation of the scanning unit is desired, solenoid 58 is actuated to place openings b and c of valve 57 in fluid communication and seal the supply conduit means I from the remainder of the registration unit driving means. With solenoid 58 thus energized, and after piston 20b has reset sufliciently to rotate the elongate portion of cam 38 into drivin g contact with cam follower 55c, the cam 38 will act on piston rod 55b to move piston 55a of first motor 55 to the right. Fluid expelled from this motor by the rightward movement of piston 55a will enter conduit means K. Because opening d in spool vaive unit 57 is closed, the exiting fluid will be caused to enter the rod end of sec- 7 nd hydraulic motor 56 and cause the piston Son of this motor to move to the right. Fluid discharged from motor 56 as a result of the rightward movement of piston 56:: will enter conduit means I from whence it passes through openings b and c of valve 57 and into conduit means L [for discharge into sump 41.

Each scanning increment, of course, will be of suflicient length to accommodate all feed errors normally expected to be encountered, with cam 38 being so driven and peripherally configured as to eifect the appropriate scanning duration. In certain feeding operations, as, for example where the spacing of indicia varies substantially, it may even be necessary to drive and configure cam ease as to cause scanning of the web during the entire resettingst'roke. Where indicia spacing is relatively regular, however, the limiting of the scanning to the terminal portion of the resetting stroke in the manner described economizes on scanning time. As a result, the scanning may be conducted at slow speed for short intervals without adversely effecting the overall capacity of the feeding operation.

For scanning purposes, it is necessary that scanning unit 36 translate along web 7 at the same linear speed at which the surface of feed roll 1% moves relative to Web 7 during its resetting as efiected by the counterclockwise movement of rotary piston 26b. As a result, cam means 38 mus't be peripherally proportioned so as to effect linearly 'unifonm movement of piston follower 550. While the movement of follower 55c need be uniform, it ne'ed notbe at the same speed as the relative speed between reed roll 18 and web 7. By virtue of the fluid interconnection between the cam actuated portion of the system and the scanning head translating portion, the relative sizes of the motors may be adjusted to obtain the requisite scanning speed irrespective of the rate of movement of the cam driven piston 55a.

When the elongated portion of rotary cam 38 engages the cam follower 55c, the inertia of the driving system will cause a substantial slowing of the rate of rotary movement of the rotary cam 38. This slowdown in the movement of cam 38 will, of necessity, cause the scanning speed to be less than the rate of relative movement between "the web 7 and the periphery of the feed roll 18 during the period of the resetting stroke preceding the initiation of scanning.

A control system for correlating the operation of the Work station, web feeding mechanism, and registration control mechanism is illustrated schematically in FIG- URE 3. In this illustration, the various instrumentalities in the apparatus are set forth in their context in the control network. The various system components, including switch mechanisms, are illustrated in association with their related actuating and controlling elements. Line representation have been employed to represent control signals, with block representations being utilized to represent portions or the "control system which receive control signals and transmit them to particular system components.

The operation 'of the system will be approached at the point where mold4 nears molding engagement with web 7. As mold 4 is moved upward by the piston within cylinder 6, an extensionof the mold engages limit switch 59. A signal generated by this engagement passes through portion 60 of the control network and is transmitted to solenoid 49, which had been energized to supply feed fiuid to motors 2t) and 31, to effect deenergization of this solenoid. A signal is also transmitted to cylinders 17 and 29 so as to concurrently separate idler rolls 11 and 23 from web 7. In FIGURE 3 it is to be noted that there is illustrated only the signal transmitted to cylinder 17 of the feed mechanism.

In moving downward from the web which is at rest, idler roll '11, through its supporting mechanism, engages a limit switch 61. A signal generated by this engagement is transmitted through portion 62; of the control network to concurrently energize

solenoids

48 and 50, so as to place motors 2t) and 31 in parallel fluid connection and initiate counterclockwise or resetting movement of the rotary pistons of these motors.

After a predetermined resetting movement of the cyclic motor 2%, suff cient to bring the elongate portion of cam 38 into engagement with cam follower 55c, longitudinal translation of the scanning unit under the driving infiuence of cam 38 and hydraulic motors '55 and 56 will cornmence. Prior to the initiation of the movement of fol- [lower 55c, solenoid 58 will have been actuated so as to place

motors

55 and 56 in fluid inter-communication and to separate the motors from the outside pressure source in conduit means I. While the actuation of solenoid 58 could be accomplished through a variety of means including a cam driven by rotary motor 20 or limit switch ol, the illustrated control system contemplates the actuation of this solenoid by the engagement of the upward moving mold 4!- Wi'th a limit switch 59. This engagement occurs before resetting has initiated and while follower 55c is in engagement with the circular portion of cam 38. The signal generated by the engagement passes through portion 60* of the network to solenoid 53.

The scanning unit will move longitudinally er the web 7 in a direction opposite "to the feed direction, i.e. to the right in the illustrated arrangement until light is reflected from the light source 35 into photocell 36 by a light reflective registration indicia 3-7. In response to this location of the registration indicia 37, a signal is transmitted through control portion '63 of the control network to deener'gize solenoid 48 and actuate the pistons in cylinders 17 and 29 so as to effect the closing of idler rolls 11 and 23. As before, for convenience purposes, the control circuit has been illustrated only with respect to the signal transmitted to'the cylinders 17 and the signal transmitted to cylinder 29 has been omitted.

Solenoid 4% when deenergized is 'eifective to terminate the resetting of hydraulic motor This deenergization blocks the discharge new path through spool valve 45 which provides communication between conduit means E and F. With conduit means E thus blocked, discharge from opening 2 of motor 2i) is prevented so as to hydraulically block the resetting movement of rotary piston 2%. The near instantaneous response of the system to the indicia responsive photocell signal insures prompt and accurate termination of the resetting of feed motor 20.

It should be noted that while the photocell signal terminates the resetting of motor 20', it is not employed to terminate the resetting of motor 31. The spool of valve 46 in the solenoid deenergized position, blocks only the discharge from motor 20. Valve 53 in the resetting flow discharge path leading from motor 20 and valve 54 in the path leading from motor 31 are adjusted so that the resetting of outfeed motor 31 will occur at a more rapid rate than the resetting of feed motor Zil. As a result the resetting of motor 31 will terminate by abutting engagement of the rotary piston 31b with the right side of partition 31d While rotary piston 20b is still resetting.

To insure that undesired photocell signals are not imposed on the control network as, for example, during feeding, it is desired that the photocell circuit itself be rendered operative only during the resetting operation. For this purpose, there is provided the motor driven rotary cam 39 which, during the resetting and before the initiation of scanning, engages a limit switch 64. This engagement transmits a signal through control portion of the control network to energize the photocell as.

Returning to the operation of the circuit at the point of emanation of the photocell generated signal, as idler roll 11 closes at the conclusion of the resetting of the cyclic motor 2n, the limit switch 61 is disengaged from the supporting mechanism associated with roll 11. This disengagement transmits a signal through control portions 66 of the network to deenergize solenoid 50. This deenergization of solenoid t converts the fluid connection between the motors 2i and 31 from parallel to series in preparation for the succeeding feed stroke.

While feeding may be initiated in a variety of Ways, in the illustrated system it is accomplished by downward movement of the mold 4. In moving downward out of engagement with a molded portion of web 7, the mold 4 will engage limit switch 553. This engagement transmits a signal through control portion 67 of the network to solenoid 49 to initiate the flow of piston actuating fluid to the series connected cyclic motors. The engagement may also be employed to deenengize the photocell 36.

At the completion of a feedstroke, the cam 40, rotatably driven by feed motor 20, engages a limit switch 68. The signal generated by this engagement is transmitted through portion 69 of the circuit to initiate recycling or upward movement of the piston contained within cylinder 6. As the mold 4 moves upward, it will again engage the limit switch 59 in its upward movement to reinitiate the resetting portion of the cycle. Normally limit switch 68 would be actuated shortly before the completion of the clockwise or feeding movement of the

rotary pistons

20b and 31b. It is thus contemplated that the mold 4, in its upward movement, would not engage the limit switch 59 until after the

rotary pistons

20b and 31b had completed their feed strokes and engaged the abutments 20d and 31d respectively.

In order that the pistons 55a and 56a of the scanning unit driving mechanism may be reset, it is necessary that solenoid 58 be deenergized at some time subsequent to the conclusions of scanning. This deenergization could be effected in several ways, including use of the means which control the initiation of web feeding or cam and switch means actuated by feed motor 20. In the illustrated system, however, there is envisioned a signal generated by the engagement of the mold 4 with a lower limit switch 70 during downward movement of the mold 4, which signal is transmitted through control portion 71 to deenergize solenoid 58. Through this arrangement, solenoid 58 will be deenergized at the completion of the scanning operation. The time involved until the mold 4 has moved down to switch 74 will insure that deenergization does not occur until after the elongate portion of cam 38 has ro tated past follower 55c. Obviously this solenoid must remain deenergized for sufficient time to allow resetting of the piston 55a and 56a before the initiation of a succeeding scanning operation.

The advantages of the system heretofore described are several with respect to both structure and function. By gauging each feed stroke prior to its initiation, absolute registration of each increment fed to the mold is insured. As the web is at rest during the scanning operation which determines the duration of each feed stroke, no interference with the web is occasioned by the scanning operation. With the scanning being conducted at relatively low speed, the accuracy of the scanning and consequent registration is enhanced. Because the scanning is conducted between feed strokes, the feed strokes themselves may be rapid without adversely effecting web registration.

The accumulator and flow restrictor combination which effect deceleration of the cyclic motors at the end of the feed strokes avoid the imposition of potentially damaging strains on the web and the feed apparatus which would result from abruptly terminating the strokes.

The cyclic hydraulic drive motors facilitate positive control of each feed stroke. The rotary character of the motors in the preferred embodiment provides a structurally efiicient drive arrangement. The hydraulic linkage in the registration system, between the cam driven motor and the scanning head driving motor allows for flexibility in the positioning of the scanning unit and provides means which may accommodate for speeds of the 19 cam driven motor which do not correspond to the desired scanning speed.

The unique hydraulic circuit for placing the rotary piston motors in series connection during concurrent feeding and outfeeding and in parallel connection during resetting is especially advantageous. When connected in series, the feed motor, in effect, drives the outfeed motor. In this way not only is concurrent movement of the motors insured, but undue tensioning and breakage of webs is avoided which could result from the initiation of outfeed motor movement prior to the initiation of feed motor movement. The parallel fluid connection during resetting enables, if desired, a relatively rapid resetting motion prior to scanning.

While the invention has been described with respect to a preferred embodiment which affords particular advantages, it will be readily apparent to those skilled in the art that certain modifications may be effected without departing from the spirit of the invention. The scanning unit, for example, rather than being of the photocell variety, may operate in response to radioactive, pneumatic, mechanical or optical sensing arrangements. While the interruption of the resetting operation has been disclosed as being accomplished by interrupting the discharge flow of reset actuating fluid, the reset termination may be accomplished in a variety of other fashions. For example, the motion of the scanning unit itself may be caused to cease when an indicia is located. With the scanning unit stopped, the reset movement of piston 20b would be blocked by the drive chain comprising rotary cam 38, piston 55a, conduit means K and piston 56a.

While the rotary piston, cyclic motors afford particular operational advantages, it is apparent that other drive mechanisms, including mechanical or electrical units, may be employed even though there may be some sacrifice in structural efficiency. Similarly, the drive mechanism and control components are not necessarily limited to the specifically illustrated forms.

While scanning during only the terminal portion of the resetting operation economizes on scanning time and contribues to the scanning operation, it may be desired during certain feeding operations to scan during the entire extent of the resetting strokes.

The suggested modifications, as well as others, may readily occur to those versed in the web feeding registration art, it being understood that scope of the invention is deemed to be defined in the appended claims.

I claim:

1. In an apparatus for effecting controlled intermittent feeding of a web which includes means for feeding said web, scanning means adapted to longitudinally translate along said web to locate registration indicia, and driving means for translating said scanning means along said web, the improvement in said driving means comprising:

a first hydraulic motor having a first piston driven by said means for feeding said web,

and a second hydraulic motor fluid connected to said first hydraulic motor and having a second piston driven by the fluid displaced by said first piston of said first hydraulic motor, with said second piston of said second hydraulic motor being in driving enengagement with said scanning means.

2. An hydraulic apparatus for effecting controlled intermittent feeding of a web having spaced, light reflective registration indicia, said apparatus comprising:

cyclic feed means for imparting intermittent feed strokes to said web, said feed means including web engaging and advancing means,

feed disengaging means [for placing said web engaging and advancing means out of driving engagement with said web, and cyclic hydraulic motor means including rotary piston means for actuating said engaging and advancing means to impart said intermittent feed strokes to said web;

Ieed stroke resetting means for restoring said rotary 1 i piston means :to a feed stroke initiating position at the end of each feed stroke after said web engaging and advancing means has been placed out of driving engagement wtih said web;

feed stroke adjusting means for determining the initiating position of each feed stroke during the restoring of said rotary piston means, said adjusting means including photocell scanning means adapted to longitudinally translate along said Web in a direction opposite to the feed direction to locate a light reflective registration indicia,

and control means responsive to the location of said indicia by said scanning means for terminating the restoring of said rotary piston means to thus determine said feed initiating position;

and driving means operated by said cyclic hydraulic motor means for translating said scanning means along said web, said driving means including a first hydraulic motor having a first piston driven by said rotary piston means,

and a second hydraulic motor fluid connected to said first hydraulic motor and having a second piston driven by the fluid displaced by said first piston of said first hydraulic motor with said second piston of said second hydraulic motor being in driving engagement with said photocell scanning means.

3. An hydraulic apparatus for effecting controlled intermittent feeding of a web having spaced light reflective registration indicia, said apparatus comprising:

cyclic feed means for imparting intermittent feed strokes to said web, said feed means including a Web engaging and advancing feed roll,

feed roll disengaging means for placing said feed roll out of driving engagement with said web,

and a cyclic hydraulic motor means including a rotary piston for actuating said feed roll to impart said intermittent feed strokes to said web;

feed stroke resetting means for restoring said rotary piston to a feed stroke initiating position at the end of each feed stroke after said feed roll has been placed out of driving engagement wtih said Web; feed stroke adjusting means for determining the initiatinig position of each feed stroke during the restoring of said rotary piston, said adjusting means including photocell scanning means adapted to longitudinally translate along said web in a direction opposite to the feed direction to locate a light reflective registration indicia,

and control means responsive to the location of said indicia by said scanning means for terminating the restoring of said rotary piston to thus determine said iced initiating position;

and driving means operated by said cyclic hydraulic motor means for translating said scanning means along said web, said driving means including a. first hydraulic motor having a first piston,

a cam driven by said rotary piston and adapted to drive said first piston of said first hydraulic motor ter a predetermined restoration or" said rotary piston,

and a second hydraulic motor fluid connected to said first hydraulic motor and having a second piston driven by the fluid displaced by said first piston of said first hydraulic motor, with said second piston of said second hydraulic motor being in driving engagement with said photocell scanning means.

4. An apparatus for effecting controlled intermittent feeding of a web having spaced registration indicia, said apparatus comprising:

cyclic feed means for imparting intermittent feed strokes to said Web;

feed stroke resetting means for restoring said feed means to a feed stroke initiating position at the end of each feed stroke while said web is at rest;

feed stroke adjusting means for determining the initiating position of each feed stroke during the restoring of said feed 1621115, said adjusting means including scanning means mounted for longitudinal translation along said web in a direction opposite to the feed direction to locate a registration indicia. driving means for moving said scanning means along said Web, and control means responsive to the location of said indicia by said scanning means for terminating the restoring of said feed means to thus determine said feed stroke intiating position; cyclic outfeed means for imparting intermittent outfeed strokes to said web concurrent with said feed strokes; outfeed stroke resetting means for restoring said outfeed means to an outfeed stroke initiating position at the end of each outfeed stroke while said web is at rest; means interconnecting said feed means in driving rela tion with said outfeed means during said concurrent feed and outfeed strokes;

and means for interrupting said driving relation during the restoring of said feed and outfeed means and for eflfecting mutually independent restoring movement of said feed and outfeed means.

5. An apparatus for effecting controlled intermittent feeding of a web as described in claim 4 and including means for causing said outfeed means to restore to an outieed stroke initiating position at a rate more rapid than that at which said feed means restores to a feed stroke initiating position.

6. An hydraulic apparatus for effecting controlled intermittent feeding of a web having spaced light reflective registration indicia, said apparatus comprising:

cyclic feed means for imparting intermittent feed strokes to said Web, said feed means including first, web engaging and advancing means, feed disengaging means for placing said web engaging and advancing means out of driving engagement with said web, and first cyclic hydraulic motor means including first rotary piston means for actuating said engaging and advancing means to impart said intermittent feed strokes to said Web; feed stroke resetting means forrestoring said first rotary piston means to a feed stroke initiating position at the end of each feed stroke after said first, web engaging and advancing means has been placed out of driving engagement with said web; and feed stroke adjusting means for determining initiating position of each feed stroke during restoring of said first rotary piston means, said justing means including photocell scanning means mounted for longitudinal translation along said web in a direction opposite to the feed direction to locate a light reflective registration indicia, driving means for moving said photocell scanning means along said web, and control means responsive to the location of said indicia by said scanning means for terminating the restoring of said first rotary piston means to thus determine said feed initiating position; cyclic outfeed means for imparting intermittent outfeed strokes to said web at a point spaced from said cyclic feed means, said outfeed means including second, web engaging and advancing means, outfeed disengaging means operable concurrently with said feed disengaging means for placing said second, web engaging and advancing means out of driving engagement with said web, and second, cyclic hydraulic motor means includthe the ad- 13 ing second rotary piston means for actuating said second, web engaging and advancing means concurrently with the actuation of said first, Web engaging and advancing means to impart said intermittent outfeed strokes to said web; outfeed stroke resetting means for restoring said second, rotary piston means at the end of each outfeed stroke to an outfeed stroke initiating position after said second, Web engaging and advancing means has been placed out of driving engagement with said web; and valve means for placing said first and second cyclic hydraulic motor means in series fluid connection during said concurrent feed and outfeed strokes and for placing said first and second cyclic hydraulic motor means in parallel fluid connection during said restoring of said first and second rotary piston means.

7. An hydraulic apparatus as described in claim 6 for effecting controlled intermittent feeding of a Web, said apparatus including: means for restoring said second, cyclic hydraulic motor means of said outfeed means at a motor rapid rate than that at which said first, cyclic hydraulic motor means of said feed means is restored.

8. An hydraulic apparatus for effecting controlled intermittent feeding of a web having spaced registration indicia, said apparatus comprising:

cyclic hydraulic feed means for imparting intermittent feed strokes to said web;

feed stroke adjusting means for determining the initiating position of each feed stroke during the restoring of said feed means, said adjusting means including scanning means mounted for longitudinal translation along said web in a direction opposite to the feed direction to locate a registration indicia, driving means for moving said scanning means along said web, and control means responsive to the location of said indicia by said scanning means for terminating the restoring of said feed means to thus determine said feed initiating position; and fluid discharge means for said feed means having decelerating means for slowing the terminal portion of the feed strokes of said feed means.

9. An hydraulic apparatus for effecting controlled intermittent feeding of a web having spaced, light reflective registration indicia, said apparatus comprising:

14 cyclic feed means for imparting intermittent feed strokes to said web, said feed means including Web engaging and advancing means, feed disengaging means for placing said web engaging and advancing means out of driving engagement with said Web, and cyclic hydraulic motor means including rotary piston means for actuating said engaging and advancing means to impart said intermittent feed strokes to said web; feed stroke resetting means for restoring said rotary piston means to a feed stroke initiating position at the end of each feed stroke after said web engaging and advancing means has been placed out of driving engagement with said Web; and feed stroke adjusting means for determining the initiating position of each feed stroke during the restoring of said rotary piston means, said adjusting means including photocell scanning means mounted for longitudinal translation along said web in a direction opposite to the feed direction to locate a light reflective registration indicia, driving means for moving said photocell scanning means along said web, and control means responsive to the location of said indicia by said scanning means for termihating the restoring of said rotary piston means to thus determine said feed initiating position; and fluid discharge means for said cyclic hydraulic motor means having decelerating means for slowing the terminal portion of the feed strokes of said rotary piston means, said decelerating means including a discharge line in fluid communication with said cyclic hydraulic motor means, a discharge flow restricting orifice in series fluid connection with said discharge line, and a piston accumulator in series fluid connection with said discharge line and parallel fluid connection with said orifice.

References Qitetl in the file of this patent UNITED STATES PATENTS 2,029,919 Fuller Feb. 4, 1936 2,100,445 Le Blew Nov. 30, 1937 2,425,382 Lubbert Aug. 12, 1947 2,780,269 Hill Feb. 5, 1957 2,862,233 Brown Dec. 2, 1958 2,983,955 Gajdosik May 16, 1961 2,986,076 Flint et a1. May 30, 196 1 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 ll5 999 December 31 1963 Frederick Jo Wythe It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 10, line 75,, for "reed" read feed column 11 line 4 for "wtih" read with column 13 line 21 for "motor" read more Signed and sealed this 23rd day of June 1964o SEAL fittest:

EDWARD J. BRENNER Commissioner of Patents ERNEST W. SWIDER Aitesting Officer

Claims

2. AN HYDRAULIC APPARATUS FOR EFFECTING CONTROLLED INTERMITTENT FEEDING OF A WEB HAVING SPACED, LIGHT REFLECTIVE REGISTRATION INDICIA, SAID APPARATUS COMPRISING: CYCLIC FEED MEANS FOR IMPARTING INTERMITTENT FEED STROKES TO SAID WEB, SAID FEED MEANS INCLUDING WEB ENGAGING AND ADVANCING MEANS, FEED DISENGAGING MEANS FOR PLACING SAID WEB ENGAGING AND ADVANCING MEANS OUT OF DRIVING ENGAGEMENT WITH SAID WEB, AND CYCLIC HYDRAULIC MOTOR MEANS INCLUDING ROTARY PISTON MEANS FOR ACTUATING SAID ENGAGING AND ADVANCING MEANS TO IMPART SAID INTERMITTENT FEED STROKES TO SAID WEB; REED STROKE RESETTING MEANS FOR RESTORING SAID ROTARY PISTON MEANS TO A FEED STROKE INITIATING POSITION AT THE END OF EACH FEED STROKE AFTER SAID WEB ENGAGING AND ADVANCING MEANS HAS BEEN PLACED OUT OF DRIVING ENGAGEMENT WITH SAID WEB; FEED STROKE ADJUSTING MEANS FOR DETERMINING THE INITIATING POSITION OF EACH FEED STROKE DURING THE RESTORING OF SAID ROTARY PISTON MEANS, SAID ADJUSTING MEANS INCLUDING PHOTOCELL SCANNING MEANS ADAPTED TO LONGITUDINALLY TRANSLATE ALONG SAID WEB IN A DIRECTION OPPOSITE TO THE FEED DIRECTION TO LOCATE A LIGHT REFLECTIVE REGISTRATION INDICIA, AND CONTROL MEANS RESPONSIVE TO THE LOCATION OF SAID INDICIA BY SAID SCANNING MEANS FOR TERMINATING THE RESTORING OF SAID ROTARY PISTON MEANS TO THUS DETERMINE SAID FEED INITIATING POSITION; AND DRIVING MEANS OPERATED BY SAID CYCLIC HYDRAULIC MOTOR MEANS FOR TRANSLATING SAID SCANNING MEANS ALONG SAID WEB, SAID DRIVING MEANS INCLUDING A FIRST HYDRAULIC MOTOR HAVING A FIRST PISTON DRIVEN BY SAID ROTARY PISTON MEANS, AND A SECOND HYDRAULIC MOTOR FLUID CONNECTED TO SAID FIRST HYDRAULIC MOTOR AND HAVING A SECOND PISTON DRIVEN BY THE FLUID DISPLACED BY SAID FIRST PISTON OF SAID FIRST HYDRAULIC MOTOR WITH SAID SECOND PISTON OF SAID SECOND HYDRAULIC MOTOR BEING IN DRIVING ENGAGEMENT WITH SAID PHOTOCELL SCANNING MEANS.